"""Instrumentation module for Flask framework.

"""

from newrelic.api.wsgi_application import wrap_wsgi_application
from newrelic.api.function_trace import (FunctionTrace, wrap_function_trace,
        FunctionTraceWrapper)
from newrelic.api.transaction import current_transaction

from newrelic.common.object_wrapper import (wrap_function_wrapper,
        function_wrapper)
from newrelic.common.object_names import callable_name
from newrelic.core.config import ignore_status_code

def framework_details():
    import flask
    return ('Flask', getattr(flask, '__version__', None))

def should_ignore(exc, value, tb):
    from werkzeug.exceptions import HTTPException

    # Werkzeug HTTPException can be raised internally by Flask or in
    # user code if they mix Flask with Werkzeug. Filter based on the
    # HTTP status code.

    if isinstance(value, HTTPException):
        if ignore_status_code(value.code):
            return True

@function_wrapper
def _nr_wrapper_handler_(wrapped, instance, args, kwargs):
    transaction = current_transaction()

    if transaction is None:
        return wrapped(*args, **kwargs)

    name = getattr(wrapped, '_nr_view_func_name', callable_name(wrapped))

    # Set priority=2 so this will take precedence over any error
    # handler which will be at priority=1.

    transaction.set_transaction_name(name, priority=2)

    with FunctionTrace(name):
        return wrapped(*args, **kwargs)

def _nr_wrapper_Flask_add_url_rule_input_(wrapped, instance, args, kwargs):
    def _bind_params(rule, endpoint=None, view_func=None, **options):
        return rule, endpoint, view_func, options

    rule, endpoint, view_func, options = _bind_params(*args, **kwargs)

    if view_func is not None:
        view_func = _nr_wrapper_handler_(view_func)

    return wrapped(rule, endpoint, view_func, **options)

def _nr_wrapper_Flask_views_View_as_view_(wrapped, instance, args, kwargs):
    view = wrapped(*args, **kwargs)
    view._nr_view_func_name = '%s:%s' % (view.__module__, view.__name__)
    return view

@function_wrapper
def _nr_wrapper_endpoint_(wrapped, instance, args, kwargs):
    def _bind_params(f, *args, **kwargs):
        return f

    f = _bind_params(*args, **kwargs)

    return wrapped(_nr_wrapper_handler_(f))

def _nr_wrapper_Flask_endpoint_(wrapped, instance, args, kwargs):
    return _nr_wrapper_endpoint_(wrapped(*args, **kwargs))

def _nr_wrapper_Flask_handle_http_exception_(wrapped, instance, args, kwargs):
    transaction = current_transaction()

    if transaction is None:
        return wrapped(*args, **kwargs)

    name = callable_name(wrapped)

    # Because we use priority=1, this name will only be used in cases
    # where an error handler was called without an actual request
    # handler having already being called.

    transaction.set_transaction_name(name, priority=1)

    with FunctionTrace(name):
        return wrapped(*args, **kwargs)

def _nr_wrapper_Flask_handle_exception_(wrapped, instance, args, kwargs):
    transaction = current_transaction()

    if transaction is None:
        return wrapped(*args, **kwargs)

    # The Flask.handle_exception() method is always called in the
    # context of the except clause of the try block. We can therefore
    # rely on grabbing current exception details so we have access to
    # the addition stack trace information.

    transaction.record_exception(ignore_errors=should_ignore)

    name = callable_name(wrapped)

    with FunctionTrace(name):
        return wrapped(*args, **kwargs)

@function_wrapper
def _nr_wrapper_error_handler_(wrapped, instance, args, kwargs):
    transaction = current_transaction()

    if transaction is None:
        return wrapped(*args, **kwargs)

    name = callable_name(wrapped)

    # Because we use priority=1, this name will only be used in cases
    # where an error handler was called without an actual request
    # handler having already being called.

    transaction.set_transaction_name(name, priority=1)

    with FunctionTrace(name):
        return wrapped(*args, **kwargs)

def _nr_wrapper_Flask__register_error_handler_(wrapped, instance, args, kwargs):
    def _bind_params(key, code_or_exception, f):
        return key, code_or_exception, f

    key, code_or_exception, f = _bind_params(*args, **kwargs)

    f = _nr_wrapper_error_handler_(f)

    return wrapped(key, code_or_exception, f)

def _nr_wrapper_Flask_try_trigger_before_first_request_functions_(
        wrapped, instance, args, kwargs):

    transaction = current_transaction()

    if transaction is None:
        return wrapped(*args, **kwargs)

    if not instance.before_first_request_funcs:
        return wrapped(*args, **kwargs)

    if instance._got_first_request:
        return wrapped(*args, **kwargs)

    name = callable_name(wrapped)

    transaction.set_transaction_name(name)

    with FunctionTrace(name):
        return wrapped(*args, **kwargs)

def _nr_wrapper_Flask_before_first_request_(wrapped, instance, args, kwargs):
    def _params(f, *args, **kwargs):
        return f, args, kwargs

    f, _args, _kwargs = _params(*args, **kwargs)
    f = FunctionTraceWrapper(f)

    return wrapped(f, *_args, **_kwargs)

@function_wrapper
def _nr_wrapper_Flask_before_request_wrapped_(wrapped, instance, args, kwargs):
    transaction = current_transaction()

    if transaction is None:
        return wrapped(*args, **kwargs)

    name = callable_name(wrapped)

    transaction.set_transaction_name(name)

    with FunctionTrace(name):
        return wrapped(*args, **kwargs)

def _nr_wrapper_Flask_before_request_(wrapped, instance, args, kwargs):
    def _params(f, *args, **kwargs):
        return f, args, kwargs

    f, _args, _kwargs = _params(*args, **kwargs)
    f = _nr_wrapper_Flask_before_request_wrapped_(f)

    return wrapped(f, *_args, **_kwargs)

def _nr_wrapper_Flask_after_request_(wrapped, instance, args, kwargs):
    def _params(f, *args, **kwargs):
        return f, args, kwargs

    f, _args, _kwargs = _params(*args, **kwargs)
    f = FunctionTraceWrapper(f)

    return wrapped(f, *_args, **_kwargs)

def _nr_wrapper_Flask_teardown_request_(wrapped, instance, args, kwargs):
    def _params(f, *args, **kwargs):
        return f, args, kwargs

    f, _args, _kwargs = _params(*args, **kwargs)
    f = FunctionTraceWrapper(f)

    return wrapped(f, *_args, **_kwargs)

def _nr_wrapper_Flask_teardown_appcontext_(wrapped, instance, args, kwargs):
    def _params(f, *args, **kwargs):
        return f, args, kwargs

    f, _args, _kwargs = _params(*args, **kwargs)
    f = FunctionTraceWrapper(f)

    return wrapped(f, *_args, **_kwargs)

def instrument_flask_views(module):
    wrap_function_wrapper(module, 'View.as_view',
            _nr_wrapper_Flask_views_View_as_view_)

def instrument_flask_app(module):
    wrap_wsgi_application(module, 'Flask.wsgi_app',
            framework=framework_details())

    wrap_function_wrapper(module, 'Flask.add_url_rule',
            _nr_wrapper_Flask_add_url_rule_input_)

    if hasattr(module.Flask, 'endpoint'):
        wrap_function_wrapper(module, 'Flask.endpoint',
                _nr_wrapper_Flask_endpoint_)

    wrap_function_wrapper(module, 'Flask.handle_http_exception',
            _nr_wrapper_Flask_handle_http_exception_)

    # Use the same wrapper for initial user exception processing and
    # fallback for unhandled exceptions.

    if hasattr(module.Flask, 'handle_user_exception'):
        wrap_function_wrapper(module, 'Flask.handle_user_exception',
                _nr_wrapper_Flask_handle_exception_)

    wrap_function_wrapper(module, 'Flask.handle_exception',
            _nr_wrapper_Flask_handle_exception_)

    # The _register_error_handler() method was only introduced in
    # Flask version 0.7.0.

    if hasattr(module.Flask, '_register_error_handler'):
        wrap_function_wrapper(module, 'Flask._register_error_handler',
                _nr_wrapper_Flask__register_error_handler_)

    # Different before/after methods were added in different versions.
    # Check for the presence of everything before patching.

    if hasattr(module.Flask, 'try_trigger_before_first_request_functions'):
        wrap_function_wrapper(module,
                'Flask.try_trigger_before_first_request_functions',
                _nr_wrapper_Flask_try_trigger_before_first_request_functions_)
        wrap_function_wrapper(module, 'Flask.before_first_request',
                _nr_wrapper_Flask_before_first_request_)

    if hasattr(module.Flask, 'preprocess_request'):
        wrap_function_trace(module, 'Flask.preprocess_request')
        wrap_function_wrapper(module, 'Flask.before_request',
                _nr_wrapper_Flask_before_request_)

    if hasattr(module.Flask, 'process_response'):
        wrap_function_trace(module, 'Flask.process_response')
        wrap_function_wrapper(module, 'Flask.after_request',
                _nr_wrapper_Flask_after_request_)

    if hasattr(module.Flask, 'do_teardown_request'):
        wrap_function_trace(module, 'Flask.do_teardown_request')
        wrap_function_wrapper(module, 'Flask.teardown_request',
                _nr_wrapper_Flask_teardown_request_)

    if hasattr(module.Flask, 'do_teardown_appcontext'):
        wrap_function_trace(module, 'Flask.do_teardown_appcontext')
        wrap_function_wrapper(module, 'Flask.teardown_appcontext',
                _nr_wrapper_Flask_teardown_appcontext_)

def instrument_flask_templating(module):
    wrap_function_trace(module, 'render_template')
    wrap_function_trace(module, 'render_template_string')

def _nr_wrapper_Blueprint_endpoint_(wrapped, instance, args, kwargs):
    return _nr_wrapper_endpoint_(wrapped(*args, **kwargs))

@function_wrapper
def _nr_wrapper_Blueprint_before_request_wrapped_(wrapped, instance,
        args, kwargs):

    transaction = current_transaction()

    if transaction is None:
        return wrapped(*args, **kwargs)

    name = callable_name(wrapped)

    transaction.set_transaction_name(name)

    with FunctionTrace(name):
        return wrapped(*args, **kwargs)

def _nr_wrapper_Blueprint_before_request_(wrapped, instance, args, kwargs):
    def _params(f, *args, **kwargs):
        return f, args, kwargs

    f, _args, _kwargs = _params(*args, **kwargs)
    f = _nr_wrapper_Blueprint_before_request_wrapped_(f)

    return wrapped(f, *_args, **_kwargs)

def _nr_wrapper_Blueprint_before_app_request_(wrapped, instance,
        args, kwargs):

    def _params(f, *args, **kwargs):
        return f, args, kwargs

    f, _args, _kwargs = _params(*args, **kwargs)
    f = _nr_wrapper_Blueprint_before_request_wrapped_(f)

    return wrapped(f, *_args, **_kwargs)

def _nr_wrapper_Blueprint_before_app_first_request_(wrapped, instance,
        args, kwargs):

    def _params(f, *args, **kwargs):
        return f, args, kwargs

    f, _args, _kwargs = _params(*args, **kwargs)
    f = FunctionTraceWrapper(f)

    return wrapped(f, *_args, **_kwargs)

def _nr_wrapper_Blueprint_after_request_(wrapped, instance, args, kwargs):
    def _params(f, *args, **kwargs):
        return f, args, kwargs

    f, _args, _kwargs = _params(*args, **kwargs)
    f = FunctionTraceWrapper(f)

    return wrapped(f, *_args, **_kwargs)

def _nr_wrapper_Blueprint_after_app_request_(wrapped, instance, args, kwargs):
    def _params(f, *args, **kwargs):
        return f, args, kwargs

    f, _args, _kwargs = _params(*args, **kwargs)
    f = FunctionTraceWrapper(f)

    return wrapped(f, *_args, **_kwargs)

def _nr_wrapper_Blueprint_teardown_request_(wrapped, instance, args, kwargs):
    def _params(f, *args, **kwargs):
        return f, args, kwargs

    f, _args, _kwargs = _params(*args, **kwargs)
    f = FunctionTraceWrapper(f)

    return wrapped(f, *_args, **_kwargs)

def _nr_wrapper_Blueprint_teardown_app_request_(wrapped, instance,
        args, kwargs):

    def _params(f, *args, **kwargs):
        return f, args, kwargs

    f, _args, _kwargs = _params(*args, **kwargs)
    f = FunctionTraceWrapper(f)

    return wrapped(f, *_args, **_kwargs)

def instrument_flask_blueprints(module):
    wrap_function_wrapper(module, 'Blueprint.endpoint',
            _nr_wrapper_Blueprint_endpoint_)

    if hasattr(module.Blueprint, 'before_request'):
        wrap_function_wrapper(module, 'Blueprint.before_request',
                _nr_wrapper_Blueprint_before_request_)
    if hasattr(module.Blueprint, 'before_app_request'):
        wrap_function_wrapper(module, 'Blueprint.before_app_request',
                _nr_wrapper_Blueprint_before_app_request_)
    if hasattr(module.Blueprint, 'before_app_first_request'):
        wrap_function_wrapper(module, 'Blueprint.before_app_first_request',
                _nr_wrapper_Blueprint_before_app_first_request_)

    if hasattr(module.Blueprint, 'after_request'):
        wrap_function_wrapper(module, 'Blueprint.after_request',
                _nr_wrapper_Blueprint_after_request_)
    if hasattr(module.Blueprint, 'after_app_request'):
        wrap_function_wrapper(module, 'Blueprint.after_app_request',
                _nr_wrapper_Blueprint_after_app_request_)

    if hasattr(module.Blueprint, 'teardown_request'):
        wrap_function_wrapper(module, 'Blueprint.teardown_request',
                _nr_wrapper_Blueprint_teardown_request_)
    if hasattr(module.Blueprint, 'teardown_app_request'):
        wrap_function_wrapper(module, 'Blueprint.teardown_app_request',
                _nr_wrapper_Blueprint_teardown_app_request_)
